SER Cable

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romeo

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NEC 2008 clarifies that Table 310.15(B)(6) can only be used for cables that carry 100% of the dwelling unit load. Also 338.10 (B)(4) that it must comply with with requirements of Part 2 of 334. Section 334.80 Ampacity shall be in accordance with 60 degrees C.

For the interior wiring from a 200amp main disconnect to a service panel or from a 100 amp breaker in a service panel to a interior sub-panel,using aluminum conductors I would need 300mcm for the service panel and 1/0 for the sb-panel correct ?
 
I don't see any question concerning the 1/0AL SE to the sub-panel.
I think it's a "catch 22" and makes no sesne to me, but as long as the SE contains conductors listed in 310.15(B)(6) and meets the "all loads" requirement, a 4/0 al appars to still be acceptable.
Logic tells me I'm wrong, and perhaps someone will prove that here.
 
Is the first sub panel the main panel for the home that is going to have all of the branch circuits? If so the main feeders to the first sub would be considerd the main feeder so no it would not be required to up size the feeders to the larger size of 300 MCM but yes from the main panel to the other sub panel it would be required to up size to the 1/0.
 
romeo said:
NEC 2008 clarifies that Table 310.15(B)(6) can only be used for cables that carry 100% of the dwelling unit load.
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I would just like to clarify that I don't believe any cable can be used for this purpose. I may be wrong but I am thinking that NM is not allowed since it is not mentioned in the conductor types.

Also 338.10 (B)(4) that it must comply with with requirements of Part 2 of 334. Section 334.80 Ampacity shall be in accordance with 60 degrees C.
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Correct

For the interior wiring from a 200amp main disconnect to a service panel or from a 100 amp breaker in a service panel to a interior sub-panel,using aluminum conductors I would need 300mcm for the service panel and 1/0 for the sb-panel correct ?[/quote]

Not sure here. If the se cable does the entire load of the 200 amp then I believe that a 4/0 alum. is still okay in spite of 338.10(B)(4). I am not sure I understand this question. If the 100 amp breaker is coming from the 200 amp panel and feeds a sub panel than it would need to be 1/0 alum.
 
SER Cable

augie47 said:
I don't see any question concerning the 1/0AL SE to the sub-panel.
I think it's a "catch 22" and makes no sesne to me, but as long as the SE contains conductors listed in 310.15(B)(6) and meets the "all loads" requirement, a 4/0 al appars to still be acceptable.
Logic tells me I'm wrong, and perhaps someone will prove that here.
Click to expand...

Thank you for your response. I am confused does 338.10(B)(4) require us to use table 310.16 in the 60degree column?
 
romeo said:
Thank you for your response. I am confused does 338.10(B)(4) require us to use table 310.16 in the 60degree column?
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Yes. But the argument can be made that 310.15(B)(6) trumps 338.10
 
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